Telephone system



18 Sheets-Sheet l Filed Nov. 2, 1940 HARRY N NEwsTEDT .I

ATTORNEYS March 30, 1943.

H. N. NEWSTDT TELEPHONE SYSTEM Filed Nov. 2, 1940 18 Sheets-Sheet 5 HARRY N. NEwsTeoT A'rroRNEY March 30,' 1943.

. H. N. NEWSTEDT TELEHONE SYSTEM Filed NOV. 2, 1940 18 Sheets-Sheet 5 March 3o,- 1943.

H. N. .NEwsTEDT 2,315,008

TELEPHONE SYSTEM i Filed Nov. 2, 1940 1.8 Sheets-Sheet 6 F.. E Mc974 .HT IJ. FIRST FEEDER TRUNK cu?. @oo y C58 s2z^ 632 Basil e625 l En 663'Cf uIl,

643-4 v fees? LC/0W INVENTOR HARRY N. NEWSTED-T ATTORNEYS March 30, 1943. HQ N. NEwsTEDT 2,315,008

TELEPHONE SYSTEM ATTORNEYS March 30, 1943. Hl. N. NEwsTEDT l 2,315,003

TELEPHONE SYSTEM Filed Nov. 2, 1940 .18 Sheets-Sheet 8 L6.9741A J874 v FIRST @PER POSITION 'AuroMnr/c /v/Gf/r OPER. Pos/NOM orf/ER om?.

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INVENTOR HARRY N.NEWSTEDT BY 1 9 l l\ l E ag et 4 'f s ATTORNEYS.

TELEPHONE SYSTEM Filed Nov. 2l, 1940 18 Sheegs-Sheet 9 05H CALL WAIT/NG APPR.

MARS/NAL ARG/NAL Raso INVENTOR HARRY N. NEWSTEDT ATTORN EY-S -March 30, 1943. H N, NEWSTEDT 2,315,008

TELEPHONE SYSTEM Filed NOV. 2, 1940 l 18 Sheets-Sheet. l2

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'H63 F154 F/G.: F1a@ Flai? Flea F/Gls F/GJO F/GJ/ FIG/2 FIG/3 F/G./4 FIG/5 FIG/6 FIG/7 FIG/8 INVENTOR HARRY N. NEWSTEDT BY l l 'E z El: a ATTORNEYS March 30,11943.

H. N. NEWSTEDT TELEPHONEl SYSTEM Filed Ny. 2,

18 Sheets-Sheet 15 v INVENTOR HARRY N. NEWSTEDT A'TToRNEYs Mmh 3o, v1943. H.- N NEWSTEDT 2,315,008

TELEPHONE SYSTEM Filed Nov. 2, 1940 18 Sheets-Sheet 14 /C/GO/ FIRST DIGIT REG/STER APPR.. 1400 March 30, `1941?. H. N. NEWsTDT I i 2,315,008

TELEPHONE SYSTEM y HARRY NjNEwsTED'r BY v u l m'ad/J'WM- ATTORNEYS H. N. NEWSTEDT TELEPHONE SYSTEM March 3o, 1943.

Filed Nov. 2. 1940 18 Sheets-Sheet 16 ATTORNEYS March 30, 1943. H N NEWSTEDT l 2,315,008

4 Y TELEPHONE SYSTEM Filed Nov. 2, 1940 18 Sheets-Sheet 17 Marh30,1943. H N NEWgTEDT 2,315,008

TELEPHONE SYSTEM Filed Nov. 2, 1940 18 'sheets-sheet 1a l l l INVENTOR HARRY N,NEWSTEUT ATTORNEYS Patented Mar. 30, 1943 TMEHONE "SYSTEBE Harry N. Newstedt, Chicago, lll., assignor to Associated Electric Laboratories, lino., Chicago, Ill., a corporation of Delaware Application November 2, 1940, Serial No. 363,960

65 Glaims.

The present invention relates to telephone systems, and more particularly to improved switching apparatus for distributing calls to a plurality of operator positions at a switchboard.

A semiautomatic telephone system including both manual and automatic exchanges conventionally comprises a manual A switchboard, an automatic B switchboard, automatic switching apparatus for setting up connections from the A switchboard to the B switchboard and an automatic switch train controllable from the B switchboard to extend connections therefrom. In a telephone system of the type noted, the switching apparatus usually comprises one or more ranks of nder switches of the hunting type, which are set into operation incident to the initiation ofl calls at the A switchboard and which then operate to search for idle paths to the B switchboard. While switching apparatus of the character noted has adequate call handling capacity when traic is moderata the call handling capacity thereof is frequently exceeded during peak traic, causing undesirable delays in handling calls under this condition.

Accordingly, it is an object of the present invention to provide in a telephone` system in cluding a switchboard,` improved switching apparatusl of the fast operating, fully directive type for extending calls thereto.

Another object of the invention is to provide in a telephone system an improved arrangement for distributing. calls to a plurality of switching links which positively prevents subsequently initiated calls from obtaining` switching link access positions preferred over the switching link access positions of previously initiatedY calls.

Another object of the. invention isy to provide in a telephone system an improvedv method oi distributing calls. to a plurality of switching links, whereby the obtaining by subsequently initiated calls of switching link access positions preferred over the switching link access positions of previously initiated calls is positively prevented.

Another object of the invention is to provide, in a telephone system including a plurality of groups of lines and a plurality of switching links having access thereto, an improved distributor or marking calling` ones of the lines batch by batch toA idle ones of the links and for causing the switching links to. seize group by group calling ones of the lines in a markedbatch.

A further object ofthe invention is to provide, in a telephone system including a plurality of groups of lines and a plurality of switching links,

an improved distributor for allotting the ones of the groups including calling lines in a predetermined order to idle ones of the switching links, whereby the calling lines in the groups are seized by idle ones of the switching links in group-by-group rotation.

A further object of the invention is to provide, in a telephone system including a plurality of groups cf lines and a plurality of switching links, an improved method of allotting the ones Vof the groups including calling lines in a predetermined order to idle onesof the switching links, whereby the calling lines in the groups are seized by idle ones of the switching links in group-by-group rotation.

A further object ofthe invention is to provide, in a telephone system including a plurality of groups of lines and a switchboard, an improved distributor for allotting in a predetermined order to idle ones of the operator positions at the switchboard the ones of the groups including calling lines, whereby the calls on the calling lines in the groups are answered at idle ones of the operator positions at the switchboard in group-by-group rotation.

A further object of the invention is to provide, in a telephone system including a plurality of groups of lines and a switchboard, an improved method of allotting in a predetermined order to idle ones of the operator positions at the switch,- board the ones of the groups including calling lines, whereby the calls on the calling lines in the groups are answered at idle` ones of the 0perator positions at the switchboard in group-by-V group rotation.

An additional object of the invention isto provide, in a telephone system including one or more trunks and a switchboard provided with l one or more operator positions, an improved arrangement of digitvregister-sender device or devices and digit register-sender controller or controllers therefor.

An additional object -of the invention is to provide, in a telephone system including a plurality of trunks and a switchboard provided with a plurality of operator positions, wherein each trunk has a digit register-sender device individually associated therewith and each operator position has a digit register-sender controller individually associated therewith, an improved arrangement for connecting the trunks to the various operator positions at the switchboard and for connecting the digit register-sender controllers to the digit register-sender devices.

A still further object of the invention is to Y quently completed.

A still further object of the invention is to provide, in a telephone system including a, plurality of lines, a switchboard and a distributor for allotting calls on the lines to the switchboard to be answered, an improved indicator associated with the switchboard for registering the number of calls waiting to be answered at the switchboard.

A still further object of the invention is to provide, in a telephone system including a plurality of lines, a switchboard provided with a plurality of operator positions and an auxiliary' operator position, an improved arrangement for distributing calls to stalfed ones of the operator positions at the switchboard and for distributing calls to the auxiliary operator position when none of the operator positions at Vthe switchboard is staffed.

The features of the present invention are illustrated as being incorporated in a telephone system comprising a central office including a manual A switchboard and an automatic B switchboard. a rst distant exchange including a manual A switchboard, a second distant exchange including an automatic switch train, and automatic switchingr apparatus in the central oice for routing calls straightforward from the manual A switchboards to the automatic B switchboard and then for extending calls from the automatic B switchboard to the automatic switch train.

In accordance with one feature of the invention, the trunks utilized inv the system comprise incoming branches accessible to the A switchboards, answering branches accessible to the automatic switching apparatus and outgoing branches associated with the automatic switch train; and the automatic switching apparatus comprises a plurality of primary switches of the fully directive type having access to the answering branches of the trunks, a plurality of feeder trunks individually associated with the primary switches, and a plurality of secondary switches of the fully directive type having access to the feeder trunks and individually associated with the operator positions at the automatic B switchboard. More particularly, each trunk is provided with a trunk circuit individual thereto and the Various branches of the trunk are normally mutually disconnected; and the trunk circuit includes a number of relays operative in different combinations to connect each two of the branches of the trunk, andja control network for the relays governable over the primary switches of the automatic switching apparatus.

In'accordance with another feature of the invention, calls on the trunks are distributed to the primary switches in accordance with an improved method, whereby there are allotted to idle ones of theprimary switchesduring a given cycle of distributions calls accumulated during a prior cycle of-distribution, and there are accumulated calls'initiated during the given cycle of distribution to be allotted during a subsequent cycle of distribution. Also, an improved cyclically operative primary switch distributor is provided for allotting the calls in the manner noted.

In accordance with another feature of the invention, an improved trunk distributor is provided which is operative cyclically to control the marking of calling ones of the trunks to the primary switches. More particularly, the arrangement comprises a plurality of marking relays individually associated with the trunks, means responsive to the operation of the marking relay associated with any one of the trunks for causing the primary switch distributor to operate an idle one of the primary switches to seize the one trunk, means responsive to the initiation of a call on any one of the trunks for preparing a point in the operating circuit of the associated one o1' the marking relays, and means governed by the trunk distributor to prepare cyclically a common point in the operating circuits of the marking relays, whereby each marking relay having a previously prepared operating circuit is operated.

In accordance with a further feature of the invention, calls on the feeder trunks are distributed to the secondary switches, and consequently to the operator positions at the automatic B switchboard. in accordance with an improved method. More particularly, the feeder trunks are arranged in two groups; and a given secondary switch is allotted repeatedly as it becomes idle intermittently to one of the groups including a calling feeder trunk in the event the other of the groups includes no calling feeder trunk, or is allotted alternately as it becomes idle intermittently to the two groups in the event each of the groups includes a calling feeder trunk; and the secondary switch is connected to a calling feeder trunk in either of the groups to which it is allotted. Also, an improved secondary switch distributor is provided for allotting the secondary switches, and consequently the operator positions at the automatic B switchboard, in the manner noted.

In accordance with` a further feature of the invention, an improved call waiting indicator is associated with the automatic B switchboard which Ycomprises a control network including a control conductor, means responsive to the presence of a call on any one of the trunks for causing the associated one of the trunk circuits to connect resistance potential therein to the control conductor, means responsive to the seizure of any one of the trunks by a primary switch for causing the associated one of the trunk circuits to disconnect resistance potential therein from the control conductor, a plurality of relays of the marginal type provided with a series operating circuit including the control conductor, whereby the relays are operated in accordance with different numbers of connections of resistance potential in the trunk circuits to the control conductor, and means for selectively operating the call waiting indicator in accordance with the operation of the relays.

In accordance with a further feature of the invention, a plurality of digit register-sender devices are individually associated with the feeder trunks and a plurality of digit register-sender controllers are individually associated with the operator positions at the vautomatic B switchboard, each of the digit register-sender devices being adapted to register and to send over the associated one of the feeder trunks one or more digits, and each of the digit register-sender controllers being adapted to control any one of the digit register-sender devices. Also, there is provided means controlled when any one of the secondary switches is operated to connect any one of the feeder trunks to the associated operator position at the automatic B switchboard for connecting the associated one of the digit register-sender controllers to the associated one of the digit register-sender devices. 

